Self-injecting syringe

Abstract

An injecting device having a protecting casing and an empty plastic ampoule therein with a needle fitted onto the empty ampoule in such a manner that its canal is open into said ampoule. A glass ampoule containing the liquid to be injected is sealed inside the casing, and an inclined member is provided for breaking the end of the glass ampoule and filling the plastic ampoule with the liquid from the glass ampoule, and a releasable compression spring is used for ejecting through the needle the liquid of the plastics ampoule after it has been filled.

Description

The present invention relates to injecting devices of the type comprising, on the one hand, a glass ampoule with a breakable tip containing a liquid to be injected and compressed gas, and, on the other hand, an hypodermic needle and communicating means between said needle and said glass ampoule.

In known devices, such communication is ensured through a flexible pipe, or a chamber defined by the device. casing itself.

These known devices are not permitting of an automatic working of the device.

The purpose of the present invention is an automatic working injection device preventing any risk for the patient and ensuring the stability and the purity of the conditioned product.

For this purpose, the injecting device according to the invention comprises a protecting casing, and inside this casing an empty plastics ampoule, a needle fitted onto said empty ampoule in such a manner that its canal is opening into said empty ampoule, a glass ampoule sealed inside the casing and containing the liquid to be injected, means to break the end of the glass ampoule, means to provide for the filling of the ampoule of plastic material with the liquid coming out of the glass ampoule, mechanical resilient means for ejecting through the needle the liquid of the plastics ampoule after it has been filled up compressioning means for said mechanical resilient means and, outside said casing, means for releasing said resilient means.

By way of non limiting examples, three embodiments of the injecting device or injecting syringe according to the invention have been illustrated on the attached drawing, on which:

FIG. 1 is a longitudinal section view of a first embodiment of the syringe.

FIG. 2 is a detailed view of a modification of the device in FIG. 1.

FIG. 3 is a detailed elevation view of a member in FIG. 2.

FIG. 4 is a plan view of the member in FIG. 3.

FIG. 5 is a longitudinal section view of another embodiment of the syringe according to the invention

And

FIG. 6 is a plan view of a member of the syringe in FIG. 5.

In the example in FIG. 1, the syringe comprises a cylindrical casing, preferably of plastics, made of two parts, screwed for example, 1 and 2; the upper part 1 contains a tensioned spring 3 bearing, on the one hand, against the bottom of the casing, and on the other hand, against a member 11 of plastics material, the purpose of which will be explained hereafter.

A sealed glass ampoule 5, itself housed in a protecting tube 6 having an opened bottom, is housed in the space freed by the spring. This ampoule is of the self-breaking type, i.e., to break its neck 7, it is but necessary to apply a pressure at its level. The liquid to be injected is contained in this ampoule together with a certain quantity 8 of compressed gas.

The end of the ampoule is capped with a tightly fitted pipe 10, made of rubber or similar material. This pipe is fitted at its lower end, onto the cylindrical projection provided therefor on the plastics member 11, the so-called piston, which is sliding with some play in the casing 2. A small filter 33, a cotton one for example, is arranged in the space provided between the tip 7 of the glass ampoule 5 and the member 11, so as to prevent, in the case when the breaking of the tip would result in glass spliting, the splits from being carried on into the ampoule 16.

The piston 11 comprises a canal 12 and a valve 13 of the ball type.

A frusto-conical member 14 is positioned, but not tightly fitted, in the corresponding frusto-conical part 15 of a plastics ampoule 16 having an accordion shape. The latter is fitted onto the support 17 of a bevelled needle 18 which is tightly engaged by friction, so as to ensure tightness, into a rubber stopper 19 which can be perforated and is accommodated in an opening provided at the lower portion of the casing.

The lower external portion 22 of casing 2 comprises a threading and two openings, having the shape of narrow slots diametrically opposite, are provided on the same member.

A milled nut 23, rigid with a member 24, adapted to rotate freely about this nut, is fitted onto this threading.

Member 24 has two lugs 26, 26' engaging the two slots 25. These two lugs are protruding inside the casing 2, sufficiently to stop the stroke of piston 11.

The protecting tube of ampoule 6 is stopped by a disc fitted therein 27 which is in contact with the end of a pusher 28 covering the upper end of the syringe and passing through the bottom of the latter.

This pusher shall necessarily be locked during the transport of the syringe by the user. The locking means is not shown on the drawing; this could be a mere pin.

The filter 33 is applied to the upper part which is in a bevelled position 29 of member 11.

The releasing device, of the type described in the U.S. Pat. No. 3,702,609 comprises hook-shaped members 30 and a ring 31. The ends 32, 32' of members 30 are holding the lower portion of member 11.

The working is as follows:

When the pusher 28 has been unlocked, the upper part of the syringe is grasped, and by applying uprightly the lower part onto a hard object, having an approximately horizontal part, and if necessary onto the ground, with interposition of a handkerchief, a sudden thrust is impelled to the pusher with the hand palm. After the combined protecting tube 6 and ampoule 5 have slid downward, the neck 7 is submitted to a force perpendicular to the axis, owing to the pitch of the upper face 29 of piston 11 and it breaks.

After waiting 2 or 3 seconds, that injection is made in the upper thigh, by applying the syringe and by pulling downward the ring 31. The ends 32, 32' of the members 30 open outwardly thus releasing piston 11. The latter, moved by the released spring 3, urges the combined ampoule 16 and needle 18 forward. The two conical parts 14 and 15 engage into each other, the valve 13 closes, the needle 18 pierces the stopper 19, enters into the flesh of the user and the crushing of ampoule 16 through the action of spring 3 injects the liquid.

The screwing or unscrewing of nut 23 enables the dose of liquid to be injected to be determined by adjustment of the length of the piston stroke.

In addition, slots 25 permit to ascertain that the ampoule 16 is satisfactorily filled up during the operation.

In the example shown in FIGS. 2 and 4, the ball-valve in FIG. 1 is replaced by a merely mechanical means preferably of plastics made of a blade 34 comprising a narrow portion 35, called "guide," a circular opening 36 of the same diameter as canal 12 of the member 29, a vent 37 and an end portion 38 with a flat-spring shape. This blade 34 is acting as a "slide" and is housed by soft friction into a groove of same profile provided in the thickness of member 29. The portion 35 engages a slide provided in the thickness of the syringe wall. This slide 39 may, if desired, be provided in a thickening of same wall. Its profile constituting, in the plastics molding technics, a "counter-stripping" arrangement, this slide may be housed at the level of the connecting face of the two syringe portions.

The spring portion of the slide maintains the latter in a pre-determined position, i.e., with its opening 36 fitting exactly canal 12, and with its vent 37 freeing a small canal 40 which enables the compressed gas to escape during the liquid transfer.

The working is as follows : on the very moment of the release, the slide obturates at the same time, through a sliding movement along slide 39, and at the time when the spring tension begins to be applied to the accordion-ampoule, the canal 12 and vent 40.

The above process chosen for stopping the ampoule and for the gas escape, enables to secure in a proof arrangement, the pliable ampoule onto the member 29.

If the plastics ampoule is conveniently filled up, which is easy to obtain, as it is but necessary to provide for a quantity of liquid slightly in excess in the glass ampoule and the liquid contained in this ampoule will not escape, whatever the position of the syringe, due to the capillarity forces.

In the example shown in FIGS. 5 and 6, the syringe differs only from that in FIG. 1 by the use of a releasing device 4 ensuring the breaking of tip 7 of the glass ampoule 5 as well as the releasing of spring 3. This spring is here bearing on the one hand against the bottom of casing 1 and on the other hand against this member 4.

This releasing device 4 has the shape of a fork, the two legs 20 of which are gripping the combined tip 7 of the glass ampoule 5 and rubber pipe 10. A canal 21 is provided near the grasping ring 32 of the releasing device 4.

It is obvious that, to actuate the syringe in this embodiment, the user presses down the releasing device until it is flush with casing 1, in taking hold of it through ring 32. The end 7 of the ampoule is broken. The gas 8 urges the liquid into the ampoule 16, emptying the glass ampoule, and escapes outwards through the space provided for by the clearance between the piston 11 and the wall, and through the canal 21 connecting the inside of the syringe to the outside.

The user waits a few seconds and then applies the bottom of the syringe to his body; he pulls off then the releasing device 4 by pulling on ring 32.

The spring 3 which is released strikes the piston 11 which urges forward the combined ampoule 16 and needle 18.

Claims

What I claim is:

1. An injecting device comprising a protecting casing, and inside this casing an empty plastics collapsible ampoule, a needle having a canal and fitted onto said empty ampoule, said needle canal opening into said empty ampoule, a glass ampoule sealed inside the casing and containing the liquid to be injected, means to break the end of the glass ampoule, means to provide for the filling of the collapsible ampoule with the liquid coming out of the glass ampoule, mechanical resilient means for both propelling said needle through said casing and ejecting through said needle the liquid of the collapsible ampoule by compressing said collapsible ampoule after it has been filled up, compressioning means for said mechanical resilient means, and outside said casing, means for releasing said resilient means.

2. An injecting device as in claim 1, wherein said means to provide for the filling of the collapsible ampoule comprises an obturating member for said empty ampoule slidably mounted in said casing and having an axial canal, a blade slidingly mounted in said obturating member and provided with a hole aligned with said axial canal, means urging said blade towards the outside of said obturating member, and means for urging said blade towards the inside of said obturating member when said resilient means are released.